This application relates to a gear pump wherein the driven gear has fewer teeth than does the drive gear.
Gear pumps are known, and typically include a pair of gears mounted for rotation about parallel axes. One of the gears is driven to rotate by a drive, such as a motor. Gear teeth on this drive gear engage gear teeth on a driven gear, and cause the driven gear to rotate with the drive gear. Pump chambers are formed by the spaces between the teeth, and move fluid from an inlet to an outlet around an outer periphery of both gears.
There are challenges when gear pumps are utilized to pump several fluids, and in particular when used to pump fuel. When utilized as a fuel pump, operating pressure and temperature have reached levels that challenge the materials currently utilized for the gear.
Typically, a high tooth count is seen as desirable to reduce contact sliding velocities and gear wear. A high tooth count is also desirable to reduce the pressure ripple in the supply and discharge lines.